A combinator is a function or operator that only refers to its arguments and operands without modifying them in any way. Symbol APL expression Bird(1) TinyAPL Diagram I \mathrm I I y Identity ⊣ / ⊢ K \mathrm K K x Kestrel ⊣ κ \kappa κ y Kite ⊢ W \mathrm W W y F y Warbler ⍨ C \mathrm C C y F x Cardinal ⍨ B \mathrm B B F (G y) Bluebird ∘ / ⍤ / ⍥ Q \mathrm Q Q G (F y) Queer ⍛ B 1 {\mathrm B}_1 B 1 F (x G y) Blackbird ⍤ Ψ \Psi Ψ (G x) F (G y) Psi ⍥ S \mathrm S S y F (G y) Starling ⟜ / ⇽ Σ \Sigma Σ (F y) G y Violet Starling ⊸ / ⇾ D \mathrm D D x F (G y) Dove ∘ / ⟜ Δ \Delta Δ (F x) G y Zebra Dove ⍛ / ⊸ Φ \Phi Φ (F y) G (H y) Phoenix «» Φ 1 \Phi_1 Φ 1 (x F y) G (x H y) Pheasant «» D 2 {\mathrm D}_2 D 2 (F x) G (H y) Dovekie ⊸ + ⟜ P \mathrm P P (y G x) F (x G y) Parrot(2) ⸚ N \mathrm N N x F (x G y) Eastern Nicator ⇽ ν \mathrm u ν (x F y) G y Western Nicator ⇾ Additionally, some other primitives have combinator-like behavior:
First seen: 2026-03-31 13:25
Last seen: 2026-03-31 15:26